A new dinosaur from the Lance Formation of Wyoming

\3 Biodiversity
fe^Heritage
^^Library

http://www.biodiversitylibrary.org

Smithsonian miscellaneous collections.

Washington :Smithsonian Institution, 1 862-1 968.
http://www.biodiversitylibrary.org/bibliography/8128

V. 61 (1914): http://www.biodiversitylibrary.org/item/95207
Page(s): No. 5, Text, Page 1 , Page 2, Figs. 1-2, Page 3, Figs. 3-5, Page 4, Page 5

Contributed by: Smithsonian Institution Libraries
Sponsored by: Smithsonian

Generated 6 July 201 1 3:06 PM
http://www.biodiversitylibrary.org/pdf3/007289600095207

This page intentionally left blank.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOLUME 61. NUMBER 5

A NEW DINOSAUR FROM THE LANCE

FORMATION OF WYOMING

BY

CHARLES W. GILMORE

**••*•«!

PW

>&<*

ORB

(Publication 2184)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION

MAY 24, 1913

Zfyt £orb $3aftimore (prese

BALTIMORE, MTi.f U. S. A.

A NEW DINOSAUR FROM THE LANCE FORMATION OF

WYOMING

By CHARLES W. GILMORE

ASSISTANT CURATOR OF FOSSIL REPTILES, U. S. NATIONAL MUSEUM

INTRODUCTION

In July, 1891, Messrs. J, B. Hatcher and W. H, Utterback dis-
covered in Wyoming an articulated skeleton of a small Orthopodous
dinosaur, Until quite recently this specimen had remained in the
original packing boxes and it was in the nature of a surprise upon
first examination to discover that it represented an undescribed form.
I therefore propose to make this animal the type of the new genus,
These elosauriis. The present paper may be considered preliminary,
as upon the completion of the preparatory work now in progress a
more detailed account of the skeletal anatomy, and a discussion of its
affinities, will be given.

THESCELOSAURUS, new genus

In the present communication the characters of this genus are
included in the description that follows of Thescelosaimis neglect us,
the type species,

THESCELOSAURUS NEGLECTUS, new species

Type, — Cat. No, 7757, U. S. N, M, This specimen consists of a
nearly complete articulated skeleton, the skull and neck being the
only important parts missing.

Type-locality. — Doegie Creek, Converse County, Wyoming,

Paratype. — Cat. No. 7758, U, S. N. M. A second individual con-
sisting of a few cervical, dorsal, and caudal vertebrae, portions of
both scapulae, ribs, bones of fore and hind feet, and portions of limb
bones. Collected by Mr. O. A, Peterson, 1889.

Locality. — Lance Creek, Converse County, Wyoming.

Horizon. — Both specimens from the Lance formation, Upper Creta-
ceous or Lower Tertiary.

Description^ — The vertebral column is present from the anterior
dorsal region to the tip of the tail. The centra of the median dorsals

Smithsonian Miscellaneous Collections, Vol. 61, No. 5

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l

measure 40 mm. in length ; arches low with thin flattened spinous pro-
cesses ; centra broadly rounded transversely, without lateral cavities ;
ends of centra slightly biconcave throughout .the series. Anterior
and median caudal s about same length as dorsals mentioned above.
Median caudals have sides of centra bisected by a sharp longitudinal
ridge.

ex.

'Srs-\$

Fig. 1. — Cervical vertebra of Thescelosaurus neglectus. Paratype. Cat, No,
7758 U. S. N. M. about Yz nat size. Viewed from left side. a. syg } anterior
zygapophysis ; d s diapophysis ; p, parapophysis.

The back of this animal is strengthened by ossified tendons extend-
ing along either side of the neural spines from the median dorsal

Fig, 2.— Left scapula of Thescelosaurus negleetus. Paratype. Cat. No. 7758
U. S. N, M. l A nat. size. Viewed externally.

region nearly to the tip of the tail A cervical pertaining to the para-
type No. 7758 (see fig. 1.) shows the sides of the centra below the
neuro-central suture to be pinched in, but to a less degree than in the
cervicals of Camptosaurus. Ventrally there is a broad, flat, roughened

s

ry

"?w.J

\tsi

Fig. 3 Fig. 4 FlG * 5

Fig, 3 — Left fore limb of Thescelosaurus neglectus. Type. Cat No, 7757
U. S. N. M. 14 nat size. Palmar view of foot shown as found in situ. C.
carpus ; H, humerus ; R, radius ; U 3 Ulna ; I, II, III, IV, and V, digits one to five.

Fig. 4, — Right hind foot of Thescelosaurus neglectus. Type. Cat No. 7757
U. S, N. M, 54 nat. size. Shown as found in situ. A, astragulus ; C\ calcaneum ;
F, distal end of fibula ; T, distal row of tarsals ; Ti f distal end of tibia ; I, II, III,
and IV, digits one to four.

Fig. 5; — Right hind leg of Thescelosaurus negtectus. Type. Cat. No. 775/
U. S. N. M. About J A nat, size. Shown as found articulated.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l

surface extending the entire length of the centrum, being wider
behind than in front. Cervical ribs free. Dorsal ribs of good length,
T-shaped above but flattening out into a broad distal portion, Cal-
cified sternal ribs present

In the pectoral arch the scapula is remarkably short with widely
expanded blade, much as in Camptosaurus (see fig. 2). The proxi-
mal portion of this bone not know 7 n. Ossified sternum present* Only
the distal half of the humerus known, but the proportions between
upper and lower bones of the fore limb appear much the same as in
other bipedal predentate dinosaurs. Carpus ossified, though its ele-
ments have not yet been definitely determined. There are five digits in
the manus, having the phalangial formula 2, 3, 4, 3, 2. The first three
digits are tipped with pointed unguals, the terminals of the fourth
and fifth, however, have been reduced to small rounded bony nodules ;
the fifth digit is borne by a small metacarpal and is comparatively
feeble. Ungual digit II missing.

The pelvic arch has not been developed sufficiently to show all its
features, but the presence of a rounded red-like pubis with a long,
slender postpubic process reaching the end of the ischium is observed.
The ischia have flattened shafts meeting on the median line but with-
out especial enlargement of their distal ends.

The femur is longer (355 mm.) than the tibia (300 mm/) ? slightly
curved and with pendant trochanter on the postero-inner face of the
shaft. As in Camp tasaurus this trochanter is developed just above the
middle of the shaft. The finger-like great trochanter is present on
the antero-external angle of the proximal end. The head is globular
and separated from the shaft by a well-defined neck. Fibula slender
with distal third closely applied to the tibia.

The astragulus and calcaneum as usual form the proximal row of
the tarsus. The distal row consists of two flattened bones articulating
with the proximal ends of metatarsals III and IV, the inner element
extending somewhat over the top of metatarsal IV, as shown in figure
4 of the articulated foot. There are four digits in the hind foot;
metatarsal I being reduced; digit V is wanting. The phalangial
formula is 2 , 3, 4, 5, o* All digits are terminated by pointed claw-like
unguals.

Typically Thescelosaurus neglectus is of moderate size, having a
total length of perhaps twelve feet, and standing a little over three
feet at the hips, The fore-limbs are somewhat more than half as long
as the hinder pair, and this disproportionate length of limb would
appear to indicate an animal normally using a bipedal mode of pro-
gression.

no. 5

NEW DINOSAUR FROM WYOMING GILMORE

Relationships. — The non-union of .the pubes in front of the sacrum,
the slender post-pubic processes extending parallel to the ischia, and
the characteristic bird-like hind feet show Thescelosaitrus to be a true
member of the suborder Orthopoda or Predentate dinosauria. Pro-
visionally this genus is here referred to the family Camptosaitridxe.
From Dryosaarus, LaosauruSj and .the English Hypsilophodon it
may at once be separated by the greater length of femur as compared
with the tibia* From Camptosanrus it is to be distinguished by the
rounded rod-like pubis as compared to the flattened blade-like pubis
of that genus. Additional characters are to be found in the fore-feet,
i. e.j an additional phalanx in digit III, and the non-coalescence of the
first metacarpal with the carpus.

The following text is generated from uncorrected OCR.
[Begin Page: No. 5]

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOLUME 61. NUMBER 5

A NEW DINOSAUR FROM THE LANCE
FORMATION OF WYOMING

BY

CHARLES W.GILMORE

(Publication 2184)

CITY OF WASHINGTON

PUBLISHED BY THE SMITHSONIAN INSTITUTION

MAY 24, 1913

[Begin Page: Text]

Z2>c £or6 <§aitimoxt (press

BALTIMORE, Ml)., U.S. A.

[Begin Page: Page 1]

A NEW DINOSAUR FROM THE LANCE FORMATION OF

WYOMING

By CHARLES W. GILMORE

ASSISTANT CURATOR OF FOSSIL RF.PTILES, U. S. NATIONAL MUSEUM

INTRODUCTION

In July, 1 89 1 , Messrs. J. B. Hatcher and W. H. Utterback dis-
covered in Wyoming an articulated skeleton of a small Orthopodous
dinosaur. Until quite recently this specimen had remained in the
original packing boxes and it was in the nature of a surprise upon
first examination to discover that it represented an undescribed form.
I therefore propose to make this animal the type of the new genus,
Thescelosaurus. The present paper may be considered preliminary,
as upon the completion of the preparatory work now in progress a
more detailed account of the skeletal anatomy, and a discussion of its
affinities, will be given.

THESCELOSAURUS, new genus

In the present communication the characters of this genus are
included in the description that follows of Thescelosaurus neglcctus,
the type species.

THESCELOSAURUS NEGLECTUS, new species

Type. — Cat. No. 7757, U. S. N. M. This specimen consists of a
nearly complete articulated skeleton, the skull and neck being the
only important parts missing.

Type-locality. — Doegie Creek, Converse County, Wyoming.

Paratype. — Cat. No. 7758, U. S. N. M. A second individual con-
sisting of a few cervical, dorsal, and caudal vertebrae, portions of
both scapulae, ribs, bones of fore and hind feet, and portions of limb
bones. Collected by Mr. O. A. Peterson, 1889.

Locality. — Lance Creek, Converse County, Wyoming.

Horizon. — Both specimens from the Lance formation, Upper Creta-
ceous or Lower Tertiary.

Description. — The vertebral column is present from the anterior
dorsal region to the tip of the tail. The centra of the median dorsals

Smithsonian Miscellaneous Collections, Vol. 61 , No. 5

[Begin Page: Page 2, Figs. 1-2]

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 61

measure 40 mm. in length ; arches low with thin flattened spinous pro-
cesses ; centra broadly rounded transversely, without lateral cavities ;
ends of centra slightly biconcave throughout the series. Anterior
and median caudals about same length as dorsals mentioned above.
Median caudals have sides of centra bisected by a sharp longitudinal
ridge.

Fig. 1 . — Cervical vertebra of These elosaurus neglectus. Paratype. Cat. No.
7758 U. S. N. M. about 2 /z nat. size. Viewed from left side. a. syg, anterior
zygapophysis ; d, diapophysis ; p, parapophysis.

The back of this animal is strengthened by ossified tendons extend-
ing along either side of the neural spines from the median dorsal

Fig. 2. — Left scapula of Thescelosaurus neglectus.
U. S. N. M. V2 nat. size. Viewed externally.

Paratype. Cat. No. 7758

region nearly to the .tip of the tail. A cervical pertaining to the para-
type No. 7758 (see fig. 1 .) shows the sides of the centra below the
neuro-central suture to be pinched in. but to a less degree than in the
cervicals of Camptosaurus. Ventrally there is a broad, flat, roughened

[Begin Page: Page 3, Figs. 3-5]

Fig. 3 Fig. 4 FIG - 5

Fig. 3. — Left fore limb of Thescelosaurus neglectus. Type. Cat. No. 7757
U. S. N. M. Y 2 nat. size. Palmar view of foot shown as found in situ. C.
carpus ; H, humerus ; R, radius ; U, Ulna ; I, II, III, IV, and V, digits one to five.

Fig. 4. — Right hind foot of Thescelosaurus neglectus. Type. Cat. No. 7757
U. S. N. M. Ya nat. size. Shown as found in situ. A, astragulus ; C, calcaneum ;
F, distal end of fibula ; T, distal row of tarsals ; Ti, distal end of tibia ; I, II, HI,
and IV, digits one to four.

Fig. 5. — Right hind leg of Thescelosaurus neglectus. Type. Cat. No. 7757
U. S. N. M. About % nat. size. Shown as found articulated.

[Begin Page: Page 4]

4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 61

surface extending' the entire length of the centrum, being wider
behind than in front. Cervical ribs free. Dorsal ribs of good length,
T-shaped above but flattening out into a broad distal portion. Cal-
cified sternal ribs present.

In the pectoral arch the scapula is remarkably short with widely

expanded blade, much as in Camptosaurus (see fig. 2). The proxi-
mal portion of this bone not known. Ossified sternum present. Only
the distal half of the humerus known, but the proportions between
upper and lower bones of the fore limb appear much the same as in
other bipedal predentate dinosaurs. Carpus ossified, though its ele-
ments have not yet been definitely determined. There are five digits in
the manus, having the phalangial formula 2, 3, 4, 3, 2. The first three
digits are tipped with pointed unguals, the terminals of the fourth
and fifth, however, have been reduced to small rounded bony nodules ;
the fifth digit is borne by a small metacarpal and is comparatively
feeble. Ungual digit II missing.

The pelvic arch has not been developed sufficiently to show all its
features, but the presence of a rounded rod-like pubis with a long,
slender postpubic process reaching the end of the ischium is observed.
The ischia have flattened shafts meeting on the median line but with-
out especial enlargement of their distal ends.

The femur is longer (355 mm.) than the tibia (300 mm.), slightly
curved and with pendant trochanter on the postero-inner face of the
shaft. As in Camptosaurus this trochanter is developed just above the
middle of the shaft. The finger-like great trochanter is present on
the antero-external angle of the proximal end. The head is globular
and separated from the shaft by a well-defined neck. Fibula slender
with distal third closely applied to the tibia.

The astragulus and calcaneum as usual form the proximal row of
the tarsus. The distal row consists of two flattened bones articulating

with the proximal ends of metatarsals III and IV, the inner element
extending somewhat over the top of metatarsal IV, as shown in figure
4 of the articulated foot. There are four digits in the hind foot;
metatarsal I being reduced; digit V is wanting. The phalangial
formula is 2, 3, 4, 5, o. All digits are terminated by pointed claw-like
unguals.

Typically Thescelosaurus neglectus is of moderate size, having a
total length of perhaps twelve feet, and standing a little over three
feet at the hips. The fore-limbs are somewhat more than half as long
as the hinder pair, and this disproportionate length of limb would
appear to indicate an animal normally using a bipedal mode of pro-
gression.

[Begin Page: Page 5]

NO. 5 NEW DINOSAUR FROM WYOMING GILMORE 5

Relationships. — The non-union of .the pubes in front of the sacrum,
the slender post-pubic processes extending- parallel to the ischia, and
the characteristic bird-like hind feet show Thescelosaurus to be a true
member of the suborder Orthopoda or Predentate dinosauria. Pro-
visionally this genus is here referred to the family Camptosauridce.
From Dryosaurus, Laosaurus, and the English Hypsilophodon it
may at once be separated by the greater length of femur as compared
with the tibia. From Camptosaurus it is to be distinguished by the
rounded rod-like pubis as compared to the flattened blade-like pubis

of that genus. Additional characters are to be found in the fore-feet,
i. e., an additional phalanx in digit III, and the non-coalescence of the
first metacarpal with the carpus.